Fully 3D printing of Carbon Black-Thermoplastic Hybrid Materials and Fast Activation for Development of Highly Stable Electrochemical Sensors

3D printing technologies have emerged as powerful tools for the development of electrochemical sensors. However, pre-treatment methods are often required to improve electrochemical properties of 3D printed sensing surface to enable higher electroanalytical performance. Herein, we report a toxic-free method for rapid activation of 3D printed electrochemical sensors. The proposed pre-treatment involves a combination of photochemical and electrochemical oxidation processes to degrade the excess of binder material impregnated on the cell surface. This strategy is simple, fast and exposes the carbon black nanoparticles to facilitate the faradaic reactions. The reported method ensured long-term stability (~ 2 months) and high heterogeneous rate constants (1.2 ± 0.3 x 10-3 cm s-1). In addition, peak currents were remarkably increased up to 353 ± 13%, clearly highlighting the potential use these 3D electrodes for electroanalytical applications. The treated electrode offered low detection limits (at µmol L-1 levels) for different analytes including metals like Cd(II) (0.009) and Pb(II) (0.006), midazolam maleate (0.54) and uric acid (0.71). Based on the achieved results, the activated, stable, and fully 3D printed electrochemical cell is very promising towards a plethora of high-performance electroanalytical applications.applications.